As a memory system used for a computer system, a solid state drive (SSD) including NAND flash memory (NAND memory) is commanding attention. The SSD has an advantage such as a high speed and a lightweight when compared to a magnetic disk device. Individual memory chips included in the NAND memory retain, in a parameter register, an operation parameter describing information that specifies a defective cell, a setting value of internal control timing, a setting value of an internal voltage, and the like. Then, a memory cell array is accessed using the operation parameter retained in the corresponding parameter register.